AT LONG LAST, the public will get a look at Treasure Island, the padlocked Navy base that Mayor Willie Brown has needlessly kept off-limits to visitors. Politics, pride and obfuscatory talk about money have made for a pointless quarrel that has embarrassed Brown.

Until now, the public was forbidden from visiting the mid-bay land, the subject of negotiations between the Navy and city over a sale price. The Navy wanted the city to pay for cleanup and security associated with visitors, but City Hall declined.

Meanwhile, the mayor's fertile mind spun out development notions while a planning body of mayoral appointees went to work. But a perception took root that the expanse of grass, homes and harbors was the mayor's private preserve, rented out for big-shot parties, but chained off for everyone else.

Is there a pattern here? Whether it's grand schemes to remodel City Hall or a line of mayoral chums bidding on public contracts, San Francisco can suffer from one-man rule.

The public's annoyance with Treasure Island was deliberated exacerbated by San Francisco's fierce politics of revenge. Brown's foes, state Senator Quentin Kopp and mayoral aspirant Clint Reilly, pushed forward Proposition K last June, which denounced the mayor's stewardship of the island. It won convincingly.

Rather than admit error, Brown backers on the Board of Supervisors ignored the public vote. A glint of fresh thought appeared last week when Supervisor Michael Yaki demanded that $60,000 be found in the $6 million Treasure Island budget to pay for public visits.

The plan offered a way to soften public indignation over City Hall's refusal to budge. The mayor initially refused, but in the end the money was found from private donors. The gates are due to swing open on weekends beginning in September.

It may be a happy ending for politicians. The rest of the world may wonder why simple curiosity and open government was thwarted. If major projects ever take shape on the flat, bay-fill base, the developments will need public support, not suspicion. Mayor Brown may be learning that his power has limits.